The temperate zone: a Summer / Autumn / Winter / Spring pattern
The Temperate zone occupies the coastal hinterland of New South Wales, much of Victoria, Tasmania, the south-eastern corner of South Australia and the south-west of Western Australia. The seasons in the temperate zone are described in terms of European seasons applied to the southern hemisphere in the following sequence:
Summer: December to February
Autumn: March to May
Winter: June to August
Spring: September to November

vic it has been amazing this year how closely the seasons have correlated with the official dates. Literally 1st march and we went from a hot dry flat summer to a wet, surf filled autumn.
June 1 and winter started on cue with a cold southerly from a tasman low.

I want Nightclub Dwight dead in his grave I want the nice-nice up in blazes

So where shall we be when el Nino kicks in? Big chance for now. We had summer right through March, a very wet April, dryish May and now it's cold. Long term, the solstice and equinox have been the definers - at least down here. I'll continue that way for now. Trev's in lala tardland

Summer begins at the summer solstice. Ends at the fall equinox , which is the beginning of fall.
It's not rocket science, but it is science.
Or maybe not. I suppose seasons are a human construct and can begin and end whenever people agree.

ajohnsen wrote: My tertiary education has been a bit like a blind woman with sudden onset diarrhea in a bathroom accessories showroom.

Birak (Dec-Jan): Dry and hot. Also known as Season of the Young.
Bunuru (Feb-Mar): Hottest part of the year. Also known as Season of Adolescence.
Djeran (Apr-May): Cooler weather begins. Also known as Season of Adulthood.
Makuru (Jun-Jul): Coldest and wettest time of the year; more frequent gales and storms. Also known as Fertility Season.
Djilba (Aug-Sept): Mixture of wet days with increasing number of clear, cold nights and pleasant warmer days. Also known as Season of Conception.
Kambarang (Oct-Nov): Longer dry periods. Also known as Season of Birth.

I was just noting that astronomical seasons are just one way of looking at it, as are meteorological seasons, as are other seasonal systems.
I do think the average person thinks 'winter' roughly defines the coldest part of the year and I would think the winter solstice would be leaving it a bit late as a start date in most regions, but maybe 'winter' has another meaning for most people.